From ce96a407adef126870b3f4a1b73529dd8aa80f49 Mon Sep 17 00:00:00 2001 From: Pan Bian Date: Fri, 30 Nov 2018 14:09:14 -0800 Subject: [PATCH] hfs: do not free node before using hfs_bmap_free() frees the node via hfs_bnode_put(node). However, it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees the node only when it is never again used. Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com Fixes: a1185ffa2fc ("HFS rewrite") Signed-off-by: Pan Bian Reviewed-by: Andrew Morton Cc: Joe Perches Cc: Ernesto A. Fernandez Cc: Viacheslav Dubeyko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hfs/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c index 98b96ff..19017d2 100644 --- a/fs/hfs/btree.c +++ b/fs/hfs/btree.c @@ -338,13 +338,14 @@ void hfs_bmap_free(struct hfs_bnode *node) nidx -= len * 8; i = node->next; - hfs_bnode_put(node); if (!i) { /* panic */; pr_crit("unable to free bnode %u. bmap not found!\n", node->this); + hfs_bnode_put(node); return; } + hfs_bnode_put(node); node = hfs_bnode_find(tree, i); if (IS_ERR(node)) return; -- 2.7.4